Dr. Kaberi Banerjee, Moolchand Medcity, New Delhi, India.
11 July 2007
There is an ongoing quest to improve pregnancy rates in patients undergoing IVF-ICSI..Numerous pharmacologic interventions have been tried, mainly empirically.A meta analysis was conducted by the group working at the Assisted Conception Unit, Guys and St .Thomas Hospital, London to evaluate the efficacy of aspirin in improving IVF-ICSI success rates. Aspirin has known antithrombotic and vasodilatory effects and thus has the potential to improve uterine and ovarian blood flow . This may then improve folliculogenesis and improve uterine receptivity. (Fertil Steril 2007,May ,Epub)
An extensive search of the literature was made for relevant literature. Seven primary articles were included in the systematic review.Weighted mean difference was calculated for continuous variables using means and standard deviations from individual studies. Fixed effect model along with random effect model used subsequently as part of sensitivity analysis was used for discrete variables. Exploration of clinical heterogeinity was planned using variation in features of population, intervention, outcome and study quality.
The meta analysis did not show a significant benefit of aspirin therapy in improving the primary outcomes like clinical pregnancy rate (RR 1.11, 95% CI 0.95) or live birth rate (RR 0.94,95% CI 0.64) in patients undergoing IVF or ICSI treatment. There was no improvement in secondary outcome rates like miscarriage rate or ectopic pregnancy rate. Of the surrogate outcomes like number of follicles, amount of gonadotrophin used , duration of stimulation, uterine artery pulsatality index, endometrial thickness and number of oocytes retrieved ,the only outcome that did show significant improvement was uterine artery pulsatality index.
The largest study conducted by Waldenstorm et al in 2004, on the role of low dose aspirin in IVF , reported a trend of beneficial effect of low dose aspirin on both clinical pregnancy rate and live birth rate.The study was excluded from the metaanalysis because it was not properly randomized, lacked concealment of allocation and it pooled results from data where a single patient contributed to more than one cycle .
The meta analysis concluded that "given the possibility of existing evidence, lack of power in available trials and the trend of benefit demonstrable in the point estimate of clinical pregnancy in this review, a double -blinded placebo- controlled randomized trial with adequate sample size may be warranted to reach a definitive answer ." Currently aspirin has not yet been proven beneficial for routine clinical use in patients undergoing IVF -ICSI.
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3.00 (out of 5)
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